The consistency observed in displacing the bear, as the animal killed by Bjarki has been noted, as has also the reason why the dragon was introduced as a substitute for the bear. It will be observed that the account of the dragon in the Siward story suggested the further development of the story in the _Hrólfssaga_. Olrik says: "I én henseende bar Sivard den digres kamp dog noget eget. De almindelige norröne dragekampe lige fra Sigurds drab på Fåvne har stadig til mål at vinde dragens guld. For Sivard digre eksisterer dette motiv ikke; han vil frelse de hjemsögte mennesker. Af alle de islandske dragekampe har kun Björn Hitdölekæmpes noget tilsvarende, og her er det næppe tilfældigt at også den er henlagt til de engelske farvande. Det er det engelske dragekamps-motiv".[52] Olrik further calls attention to the fact that in English tales the object is not to kill the dragon, but to drive it away, as Siward did. But to fit the dragon into the Bjarki story, it had to be killed in order that the blood-drinking episode might be introduced. This involved no difficulty, however; for the killing of the dragon was in harmony with Scandinavian saga-usage. But it should be observed how, in essence, the conception of the dragon in the Bjarki story harmonizes accurately with that in the Siward story. The king and his court are afflicted by the visitations of a dragon; and Bjarki puts an end to this affliction by killing the dragon, as Siward, in the corresponding situation, does by driving it away.